A basic problem about a constant dimension subspace code is to find its maximal possible size A_q(n, d, k). In this paper, we investigate constant dimension codes with parallel linkage construction and multilevel construction and obtain new lower bounds on A_q(18,6,9). By combining the Johnson type bound, we obtain new lower bounds on A_q(17,6,8). These lower bounds are larger than previously best known bounds in Heinlein et al. (2019).

中文翻译：

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来自并行链接构造和多级构造的新的恒定维子空间代码

关于恒定维子空间代码的一个基本问题是找到它的最大可能大小A _q ( n , d , k )。在本文中，我们研究了具有并行链接构造和多级构造的常数维代码，并获得了A _q (18,6,9) 的新下界。通过结合 Johnson 类型界限，我们获得了A _q (17,6,8) 的新下限。这些下限比 Heinlein 等人先前最知名的下限要大。(2019)。